Printing telegraph apparatus



' Feb. 14, 1939. w. J. Z ENNER 2,147,075

PRINTING TELEGRAPH APPARATUS FiledNov. 14, 1955 8 Sheets-Sheet l INVENTOR WALTER J: 'ZENNER star ysrznvm. (VARIABLE v ATTOR% V I FIG. 1

Feb. 14, 1939. w. J. ZENNER 2,147,075

PRINTING TELEGRAPH APPARATUS 'Filed NOV. 14, 1935 8 Sheets-Sheet 2 lOl -WALTER J. ZENNER a Arron V Feb. 14, 1939. w, ZENNER 2,147,075

PRINTING TELEGRAPH APPARATUS Filed Nov. 14, 1935 8 Sheets-Sheet 3 5 II I 'mvEm'oR WALTER J. ZENNER Arro N Y W. J. ZENNER PRINTING TELEGRAPH APPARATUS Filed Nov. 14, 1935 8 Sheets-Sheet 4 Feb. 14, 1939.

FIG l I all] I/I/IWIIWQIML 9 INVENTOR WALTER J. ZENNER A'ITORN Y Feb. 14, 1939. w. J ZENNER 2,147,075

PRINTING TELEGRAPH-APPARATUS I Filed Nov. 14, 1935 8 Sheets-Sheet 6 VENTOR J. ZENNER IN WALTER W4, Q I

A'ITOR Y Feb. 14, 1939. w, J ZENNER 2,147,075

PR INTING TELEGRAPH APPARATUS Filgd Nov. 14, 1955 s Sheets-Sheet '1 (45I5 FIG. 2| 3l8 INVENTOR WALTER J. ZENNER a IK'ITOR. Y

Feb. 14, 1939. w. J. ZENNER 2,147,075

PRINTING TELEGRAPH APPARATUS Filed Nov. 14, 1955 8 Sheets-Sheet 8 FIG. 22

' iNVENTOR WALTER J. ZENNER 2 AlTO R EY I Patented Feb. 14, 1939 PATENT OFFICE PRINTING TELEGRAPH APPARATUS Walter J. Zenner, Des Plaines, Ill., assignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application November 14, 1935, Serial No. 49,663

1': Claims. 1 (01. 178-36) This invention relates to printing telegraph apparatus and more particularly to receiving printers responsive to isochronous code signals having a single selective current impulse. ,y The primary object of the present invention is to provide an eillcient printer of simple construction operable upon the start-stop principle and comprising a minimum of operating parts.

A feature of the invention is to provide a-print- 10 ing apparatus having a single selector magnet which controls a toggle printing mechanism to produce a printed record in response to equal length code signals each'composed of two elements or opposite signalling characteristics whose 15 individual time intervals are variable but complementary so that their summation in each code signal is equal to a predetermined time constant. In accordance with the present invention the line signal for each character consists of a nocurrent starting impulse and a current definitive impulse. In the event that signal elements of opposite polarity are employed, the starting impulse will be of positive or negative current and the definitive impulse will be of negative or posi- 25 tive nature respectively. Specifically, each code signal is composed of two signal elements in which each signal element occurs but once in a code signal. The sum of the lengths of the elements in each code signal is constant, and al- 30 thougheach element varies in length, neverthe- .less each element in each code signal is the complement of the other element of that particular code signal.

lengths of the elements composing the code signal.

Upon the reception of the starting impulse, a selector magnet, which is normally energized since the idle condition of the line is of marking or current nature, releases its armature to control a power clutch, thus permitting a type wheel to rotate-which rotates in phase with a controlling element in a remote transmitter. During. the rotation of the type wheel, the selec- 45 tor magnet,-upon the termination of a starting impulse which occurs simultaneously with the beginning of the definitive impulse of opposite polarity or current condition, again becomes energized and attracts and operates its armature,

50 which action serves inthe-preferred form of the present invention to actuate a toggle printing mechanism to eilect printing at the instant when the reversal of signallingcondition occurs in the code signal cycle. In another embodiment of u the invention, cam actuated printing means is Hence, each signal is formed and each character is determined by the relative employed, which printing mechanism is similarly initiated into operation at the instant of current reversal in the code signal cycle.

A better understanding of the invention may be had from the following description taken in conjunction with the accompanying drawings, wherein like reference characters designate similar parts throughout the several views, and in which Fig. 1 is a graphical representation of the type of code signal employed in operating the various structural embodiments of the present invention;

Fig. 2 is a front elevational view of one embodiment of the invention;

Fig. 3 is a top view of the form of the invention as shown in Fig. 2 with certain parts omitted;

Fig. 4 is an elevational view of another form V of the invention;

Fig. 5 is a top view of the form of the invention shown in Fig. 4;

Fig. 6 is a sectional view of the apparatus according to Fig. 4 taken on line 6-6 of Fig. 5;

Fig. '7 is a sectional view taken on line of Fig. 6;

.Fig. 8 is a sectional view taken on line 8-8 of Fig. '7;

Fig. 9 is a sectional view taken on line 9-4 of i Fig. 10 is a front elevational view of a third form of the present invention;

Fig. 11 is a top view of the form of the invention shown in Fig. 10.with certain parts omitted; Fig. 12 is a sectional view of the form of the invention indicated in Fig. 10 taken on line l2--I2 of Fig. 11; Fig. 13 is a sectional view taken on line |3-|3 01 Fig. 12;

Fig. 14 is a sectional View taken on line [4-44 of Fig. 13; 0

Fig. 15 is a sectional view taken on line l5-l5 of Fig. 12;

Figs. 16, 17, and 18 show various operative positions of the printing and associated mechanisms of the form of the invention shown in Fig. 12;

Fig. -19 is a view showing the-motor control mechanism embodied in the apparatus according to Fig. 12;

, Fig. 20 is a front elevational view of a further form of the present invention;

Fig. 21 is a top view of theiorm oi the invention according to Fig. 20 with certain parts omitted;

Fig. 212 is a sectional view of the form or the i only a starting condition or impulse and a contiguous definitive condition or impulse. point at which the reversal of the. current or characteristic nature of the code signal occurs is determinative of the identity of the character to be printed and is the point at which printing is effected.

As indicated in Figs. 2 and 3 a motor II is shown mounted on a base plate l2. It is necessary that the speed of the motor at the receiving station be regulated so that the type wheel of the printer rotates in phase with a controlling element of. the transmitting station. Upon the armature shaft of the motor H is secured a pinion gear, not shown, which meshes with a drive gear |3 loosely carried on a shaft l4, journaled at one end in a bracket l5 mounted on the base plate l2, and the other end being journaled in a bracket l5 mounted on a front plate 20.

The gear I3 is frictionally connectedto the shaft l4 through a pair of discs l1, l8 of frictional material compressed between flange IQ of collar 22 sleeved and splined on shaft l4 and flange 2| of collar 23 fixed on shaft -|4 by set screw 23'. Compression is imparted tothe friction clutch just described by a compression spring 24 positioned between sleeved collar 22 and fixed collar 22' fixed by set screw 24' adjacent bracket II. In this manner the shaft |4 upon which type wheel 25, cam 25, stop arm 21, and star wheel 28 are fixed is given a normal urge to rotate. A selector magnet 3| is carried by a bracket 32 mounted on the base plate l2. The armature 33 of selector magnet 3| is carried upon a lever 34 pivoted at 30 to a bracket 38' mounted on the base plate l2. Lever 34 forms a part of a toggle arrangement comprising a toggle link 35 pivoted at 35 to lever 34 and at 31 to the printing hammer mechanism 42. Adjustable stops comprising eccentric screws 38 and 39 are provided to limit the oscillation of armature lever 34 controlling the toggle mechanism. Lever 34 when not attracted by the selector magnet 3| is actuated-by a spring 4| extended between lever 34 and a spring post on front plate 25.

' The printing hammer arrangement comprises a member 42 pivoted at 43 to the front plate 20, which member is provided with a vertically extending indexing projection 44 adapted to co-. operate with the notches in the star wheel 28. Member 42 also carries thereon adjacent its extremity a printing platen 45. Disposed between the platen 45 and type wheel 25 as used in Fig. 2 is a tape 45 which is guided by a suitable tape guide indicated at 41. Lever 34 is provided with a laterally disposed projection 48 which co operates with depending arm 49 of a stop lever 5| which is pivoted at 52 to an orientation bracket 53 pivotally mounted at 54 to the front plate 20. The vertical arm of lever 5| is provided with a shoulder adapted to cooperate with stop arm 21. Lever 5| normally tends to rotate in a counterclockwise direction (as viewed in Fig. 2) due to the action of a spring 55. with this arrangement lever 5| is held in position to arrest stop arm 21 when lever 34 is attracted by selector magnet 3|. Upon deenergization of selector magnet 3|, lever 34 will be actuated rightwardly by its spring 4|, permitting spring 55 to rotate lever 5| out of engagement with stop arm 21. The depending arm of orientation lever 53 is provided at its extremity with an arcuate slot adapted to be adjustably positioned angularly 'and clamped by a shoulder screw 55. In this manner the relative position between stop lever 5| and stop arm 21 can be adjusted.

Regarding the toggle printing mechanism, the lever 34 is held attracted and engages the left stop 38 during the stop position or condition of the printer, it being assumed that the normal stop condition of the signal line is marking. In this position stop lever 5| engages the stop arm 21 and prevents shaft H from rotating. The platen 45 during this condition of the mechanism is held in its lower position opposite a blank space in the type wheel. At the commencement of the starting impulse of the monopulse isochronous code signal described above, the selector magnet 3| becomes deenergized and lever 34 is actuated toward its right stop 39 by spring 4|. In the course of this movement of lever 34, platen 45 due to the toggle action of levers 34 and 35 is elevated momentarily and returned to its lower or normal position. Printing, however, is not effected since the reciprocation of the platen 45 at this moment is performed opposite a blank space in the periphery of the type wheel. Upon reversal of current at a point or instant determi-' native of the character to be printed, the armature lever 34 is again attracted by magnet 3| and directed against stop 38. In the course of this movement the platen 45 due to the toggling action is again reciprocated. At this instant, however, in the course of its reciprocation, the platen 45 is pressed against the proper character and at the same time projection 44 engages a notch in star wheel 28 corresponding to the character selected, thus performing an indexing operation and momentarily arresting the type wheel and slipping clutch wheel l3, Fig. 3, during the production of a printed character on tape 45.

Tape feeding is performed by a cam actuated tape feed mechanism comprising tape feed cam 25 carried on shaft 4. Cam 25 cooperates with one arm of tape feed lever 51 pivoted at 58 on front plate to the other arm of the tape feed lever 51 is pivoted a spacing pawl 59 which cooperates with a tape feed ratchet 6| carried on a stud shaft 52 secured to front plate 20. Lever 51 normally tends to rotate in a clockwise direction (as viewed in Fig. 2) about pivot 58 by means of a spring 53. Pawl 59 normally coacts with ratchet 5| through the instrumentality of a spring 54. With the tape feeding arrangement employed in the present embodiment, the feeding or spacing of the tape is accomplished subsequently to the printing operation. Upon initiation of rotation of shaft |4 when the lever 5| and stop arm 51 are disengaged. cam 26 rotates and gradually rotates lever 51 in a counterclockwise direction against the action of spring 53 and carries the pawl 59 into engagement with the next tooth to be acted upon in ratchet wheel 5|. At the end of the revolution of cam which is after the printing operation has been performed and immediately preceding the arrestment of stop arm 21 by lever 5|, the lever 51 will drop oil. of the high part of cam 25 and spring 63 will 'trieved from its printing position and stop lever act to rotate lever 51 sharply in a clockwise direction, thus imparting rotation through pawl 59 to ratchet 6|. This movement is imparted to a feed roller ,64' fixed to ratchet 6|. Cooperating with feed roller 64 is a pressure roller 65 mounted at the extremity of a lever 66 pivoted at 61 to front plate 20. Lever 66 through its spring 68 tends through roller 65 to exert pressure upon the tape 46 which, cooperating with feed roller 64, causes the tape during each spacing operation to be pushed toward thetype wheel. Vertical arm 69 is provided so that pressure roller 65 may be lifted from the feed roller 64 manually for purposes of adjusting or inserting the tape 46. A roll of tape 1| is mounted on the front plate 20 and the tape 46 is taken therefrom and extends over a guide roller 12before passing between feed roller 64 and pressure roller 65. An inking roller 13 of any suitable design may be provided. In the present instance the common form of roller carried on a lever 13' pivotally carried by the front plate 20 is indicated.

Operation In the operation of the printer mechanism just described, the motor II is constantly rotating in accordance with the speed of the transmitting apparatus. Through the pinion on its armature shaft the motor imparts continuous rotation to gear I3, thus through frictional connection to shaft I4, stop arm 21 is held against the latching shoulder on lever 5|. Lever 5| is maintained in latching engagement during the inoperative period of the printer by the projection 48 on lever 34, which is held attracted by selector magnet 3| due to the fact that as previously alluded to, the stop condition of the signal line is current or marking.

Due to the nature of the isochronous code signal employed in controlling the operation of the forms of printers according to the present invention, the commencement of the start impulse causes the selector magnet 3| to be 'deenergized and permits spring 4| to actuate armature lever roller is made.

34 of the toggle arrangement to its rightward position against stop 39. In response to this movement of lever 34, stop lever 5| is retracted from stop arm 21 by spring 55, permitting shaft I4 and the elements fixed thereon to rotate. As previously pointed out, the rightwa-rd'movement of lever 34 does not through the reciprocation of platen 45 effect printing because in the stop position of the type wheel a blank space thereon is presented to the printing point, thus even though the-rotation of the type wheel-has been initiated, no contact between the platen and During this movement of the shaft I4, the cam 26 thereon is acting to cause pawl 59 to engage the next tooth on the ratchet 6| preparatory to imparting the spacing movement to feed roller 64. At an instant in the cycle of rotation of shaft l4 determined by the particular character to be printed and evidenced by a reversal of the current in the line channel, the magnet 3| becomes energized and instantly effects the movement of lever 34 toward the left stop 39, thus causing, due to the toggling action of the printing mechanism, the platen 45 to rise and press tape 46 against the character selected,

5| has been rotated into position to subsequently arrest stop arm 21 at the conclusion of the cycle of rotation of shaft I4. At the end of the cycle of rotation, the tape feed arm 51 is actuated by spring 63 to rotate ratchet 6| to cause the tape to be fed one character space.

First modification In the modified form of the invention illustrated in Figs. 4 to 9 inclusive, the selector magnet has been modified to render the toggle mechanism more quickly responsive, and the printing and tape feeding mechanism for the most part has been arranged on the inside of the front plate so that the structure may .be housed by a suitable cover to expose only the type wheel and associated inking and tape propelling elements.

The framework of the printer comprises a front plate IN and a base plate I02 rigidly united. A speed regulated motor I04 is mounted upon the base plate I02 and carries on its armature shaft I05, Fig. 8, a pinion gear I06 which meshes with a gear I01 forming the driving member of a friction clutch assembly I08 on a start-stop shaft I09 mounted rotatably in two journals, a journal block 0 and a journal sleeve III. Journal block H0 is fixed in front plate IOI. Journal sleeve I II is screw threaded externally, and is provided with an integral hexagonal head II2. Bracket II 3 is fixed upon the rear face of front plate I III and is threaded internally to receive the journal sleeve III which when adjustably positioned by virtue of its screw thread and its restrained adjustably by set collar I23 on the distal end of shaft I09. A type wheel I25 having types throughout the greater portion of its circumference but having a blank or non-printing arc and having also a hub I26 is secured by means of a .set screw I21 to the front portion of shaft I09 which extends through and in front of front plate I0. Axial position of shaft I09 and type wheel I25 is maintained by abutment of hub I26 with journal block 0 and of fixed collar ||8 with'the head 2 of adjustable journal sleeve III. Back of plate IM and within the proposed housing as noted above, and fixed upon the startstop shaft I 09, Fig. 8, is a cam assembly I30 comprising asleeve having shouldered set collar I3I and bearing tape feeding cam I32, stop arm I33, star wheel I34, and spacing bushings looked upon the sleeve and against the shoulder of collar |3I by clamp nut I35.

In Fig. 6, a selector magnet I39 is shown carried on a bracket I39 mounted on the front plate IN. The magnet I38 herein employed is constructed with a core comprised of laminated plates having pole faces formed with divergent surfaces so as to cooperate with awedge-shaped armature I4 I, Fig. 5. With this form of selector magnet,-a

. greater magnetic fiux is provided and the air gap between the armature and the core is minimized through a longer operating movement as to obtain quick response and an extended angle of operation of the armature upon energization of the magnet. Armature MI is carried by an arcomprising a platen member I43 and an indexing member I5I each provided with an integral tubular sleeve I53, I53 respectively and united adjustably by a screw I52. The indexing member I5I cooperates with the star wheel I34 during the printing operation. Stop lever I55, carried upon an adjustable pivot post I56, has a hook shoulder I51, a retractile spring I63, and an operating arm I33 normally engaged by a projection I54 on armature lever I42 which normally holds the stop lever I55 against the tension of spring I63 to position the shoulder I51 normally in the path of the free end of stop arm I33. Orientation member I53 is rotatable upon a fixed pivot post I53 and is provided with an indicating arm I6I adapted to cooperate with suitable graduations or calibrations on front plate IN. The arm I53 may be retained in angular adjustment by means of slot and screw adjustments I62 to maintain a desirable interrelationship between stop lever I55 and stop arm I33 to determine the normal stop position of the type wheel.

The tape feed pawl I63 is provided with a spring I12 and a cam surface which cooperates with an eccentric adjusting stop I13, the downward movement of pawl I63 being thus limited to determine definitely the spacing movement of ratchet I 63. As pawl I63 moves downwardly it engages a tooth on ratchet I63, rotating the ratchet until the lower extremity of, pawl I63 is wedged between ratchet I 63 and stop I13. A tubular stud I13, Figs. 5 and 9, is fixed in front plate I3I and provides a bearing for a tape feed shaft I1I upon the back end of which is fixed the tape feed ratchet wheel I 63 and upon the front end of which is flxedatape feed drum I15. Tomaintain ratchet I63 in its set position while pawl I63 is retrieved to engage the next tooth, a friction drag in the form of a spring washer I14 is provided which acts as a detent. A tape pressure roller I16 on arm I11 pivoted at I13 on the back face of front plate MI and passing through an opening I33 in front plate IN is acted upon by a spring I13 to impart pressure to the tape I64 between feed drum I15 and pressure roller I16.

Operation of first modification The improved telegraphic receiving printer is illustrated in Fig. 6 in normal condition of inaction while connected to an operative but nonoperating transmission control channel. Current in a closed circuit transmission circuit not shown holds the signal responsive receiving magnet I33 in energized condition, retaining its armature' lever I 42 in attracted position; the printing arm I43 is held down by toggle link I41; the stop lever I55 is held by engagement of projection I54 and arm I63 to maintain its hook shoulder I51 in the path of stop arm I33; the stop arm I33, shaft I33 with cam I32, star wheel I34, and type wheel I25, Fig. 8, are held against rotational urge of the operative .motor I34 through friction eil'ecting-release of shaft I33 and the operating elements thereon to be initiated into rotation by motor I34. At a subsequent instant of current reversal in the code signal, the armature toggle lever 142 will again be actuated magnetically to its attracted position as shown in Fig. 6 and substantially at the midway points of its travel from stop I46 to magnet I33, the platen I43 will be pressed against a selected character on type wheel I25 to eflect printing on the tape I64 (Fig. 4) during which time the indexing member I5I will engage a notch in the star wheel 31 corresponding to the position of the selected character. This condition, however, is only eifected momentarily, and as the lever I42 continues in its responsive movement under attraction of magnet I33, the platen I43 and indexing member I5I will be lowered to inoperative position, as shown in Fig. 6. The shaft I33, however, continues to rotate until stop arm I33 again engages shoulder I51 which has been returned into its path by projection I54 acting upon arm I63 and lever I55 (12:12.18 the printing operation of armature lever During the cyclical operation of the shaft I33, the tape feeding cam I32 thereon is rotated and during its rotation acts to rock the tape feed cam follower lever I65 clockwise. Thus the tape feed pawl I63 is raised into position to engage the next tooth on tape feed ratchet I63, pawl I33 is urged into cooperative engagement with ratchet I63 by a spring I12, and after printing, and just before shaft I33 completes its cycle, the apex of cam I32 passes its follower I65 and spring III is permitted to rock the follower I65 counterclockwise, propelling pawl I63 through its return movement and driving ratchet I63 through an angle measured by one of its teeth, thus propelling the tape I64 into position to receive the impression from the next selected type on wheel I25. As in the first form of printer described, the platen I43 is reciprocated vertically during either the backward or forward movement of armature toggle lever I42, but due to the provision of a blank space upon the periphery of the type wheel I25 opposite the printing platen I43 when the type wheel is in its stop position, printing is not effected upon the reception of the starting impulse when the type wheel I25 is still motionless.

Second modification The embodiment of the invention shown in Figs. to 19 inclusive contemplates a change in the form of toggle printing mechanism wherein the toggle levers are operated mechanically under electromagnetic selective control instead of directly by power of the selector magnet as in the previous structures described. In this form of the invention, the actual printing operation is performed by a spring, the selector magnet serving merely to trip a latch to release the power stored up in the printing spring. A motor control device also is disclosed in connection with the design of the second modification. A yielding articulation is provided between the source of printing power and the point of printing impact.

According to Figs. 10, 11, and 12, the printer structure comprises a synchronous or speed regulated motor 23! mounted on a base plate 232. The armature shaft of motor 231 carries thereon a pinion gear (not shown) which meshes with a drive gear 233 carried on a shaft 234 having one end journaled in a bracket, 235 mounted on a front plate 236. The other end of the shaft 234 is journaled in front plate 236 and extends beyondfront plate 236 and supports at its outer extremity a type wheel 231. Fixed to shaft 234 on the rear of front plate 236 are a star wheel 238, tape feed cam 239,"and a stop arm 241 (Fig. 11).

Integral with gear 233 is a collar or sleeve portion 242 having formed thereon a threaded portion 243 which is a part of a motor control device associated with the present structure and which will be described hereinafter. Threaded portion 243 terminates in a flange 244. The assembly comprising gear 233. collar 242, and portions 243 and 244 is loosely mounted as a sleeve on shaft pression spring 248, interposed between member 241 and a collar 249 fixed adjustably to shaft 234. Having reference to Fig. 12, a selector magnet 25l is carried on a bracket 252 mounted on the front plate 236. Pivoted at 253 to a sub-bracket 254 carried on bracket 252 is an armature lever assembly generally indicated as 255. Assembly 255 comprises a depending armature 256 which cooperates with magnet 25l and a bent arm portion 251. To arm 251 is secured one end of a spring 258, the other end being attached to a spring post 259 mounted on front plate 236.

Pivoted at 26l to a bracket 262 mounted on front plate 236 is an arm 263 of a toggle-joint printing mechanism, the upper end of arm 263 being pivoted to a link 264 connected between lever 263 and a printing arm assembly indicated generally as 265. Attached to toggle lever 263 is one end of a printing spring 266, the other end of which is attached to a spring post, not shown, mounted on front plate 236. Toggle lever 263 is provided with a laterally disposed portion 261, adapted to cooperate with a pair of latches 268 .and 269. Latch 268 is pivoted to the lower end of the depending arm 2" of a bell crank assembly 212 pivoted at 284 and tends to rotate normally counterclockwise (as viewed in Fig. 12) due to the action of a spring 213. Latch 268 is provided at its outer extremity with a shoulder 214 which coacts with lateral portion 261 of toggle lever 263. Latch 269 is pivoted on a stud 215 fixed to the front plate 236 and tends to rotate normally in a counterclockwise direction by a spring 216 (Figs. 15 and 1'7). Latch arm 269 is provided at its outer extremity with a shoulder 211 and is adapted to cooperate under certain predetermined operating conditions with lateral portion 261 of toggle lever 263. Bell crank 212 is provided with a horizontal arm 218 terminating in' a shoulder 219 which cooperates with the cam 239 fixed to shaft 234.

- A laterally disposed lug 281, Fig. 15, on arma-- lever 212 in its position against tension of a spring 283.

The printing arm assembly 265, as shown in Figs. 13 and 14 is pivoted on a stud 286 mounted on the front plate 236 and comprises a U-shaped portion 281 having a projection 288 extending through the front plate 236 so as to coact with the type wheel 231, thus functioning as a platen. Printing arm arrangement 265 also comprises a substantially U-shaped portion 289 having one arm 29l pivotally connected to link 264 of the toggle mechanism and another arm 292 terminating in a vertical projection 293 (Fig. 12) which cooperates with the notches in the star wheel 238. The portions 281 and 289 of the printing arm arrangement 265 are yieldably connected by a compression spring 294 and a screw 295.

The assembly 212 also carries on its arm 218 an orientation arrangement comprising a screw portion 296 carrying at its lower extremity a stop element 291 which cooperates with the stop arm 24! fixed to the shaft 234. With this orientation arrangement, the angular stop position of stop arm I may be adjusted by varying the position of stop element I91 to definitely determine the proper position of the type wheel at its normal position with respect to the timing of the code signals.

Pivotally connected to arm 211 of lever 212 is a tape feed pawl 298 which cooperates with a tape feed ratchet 299. Pawl 298 is held in operative relation with ratchet I99 by means of a spring 38l. The tape feed arrangement in the presently described structure is similar to that shown in Fig. 9, the pawl 298 being provided with a cam portion adapted to cooperate with an adjustable eccentric stop screw 382 to definitely determine the spacing movement of the tape, a. detent friction washer 383 being provided to' Operation of second modification In its non-operating or waiting condition, the mechanisms just described assume the positions shown in Fig. 12, wherein lug 281 (Fig. 15)

on lever 251 holds lever 212 against the tension of spring 283. Cam 239 has passed its follower 218 and preparation to respond upon the reception of a starting impulse is provided by tension of spring 283. When, then, a starting impulse is received, the magnet 25l becomes deenergized and armature lever assembly 255 rotates in clockwise direction in response to the tension of spring 258, thereby disengaging lug 281 from notch 282, whereupon lever 212 is rotated about its pivot 284 until shoulder 219 contacts with the low portion ofwcam 239 (Fig. 16).. This action of lever 212 upon latch arm 268 will cause, through the coaction of lug 261 and shoulder 214, a backward movement of toggle lever 263 against the action of spring 266. An eccentric stop member 285 is provided to limit the back movement of toggle armf263. When toggle lever 263 has been actuated to its-backward position, lug 261 thereon isengaged by the shoulder 211 of latch arm 268, the latch arm 269 serving in this manner to hold toggle lever 263, and hence the toggle'printing mechanism, in its backward position of preparation to print, against tension of printing spring 266 as shown in Fig. 16.

through arm 211 and member291 has disengaged member-291 fromstop arm 241, thus permitting the type wheel 231, star wheel 238 and cam 239 to be driven by power of motor 231. At the instant of reversal of current indicative of the character to be printed, the magnet 251 becomes reenerglzed and causes armature assembly 256 to rotate counterclockwise, whereupon the lug 281 will act to force both latches 268 and 269 downwardly to disengage shoulder, 211 from lug 261 and to prevent the engagement of lug 261 with shoulder 214 as the toggle lever 263 is actuated sharply toward its forward position by the printing spring 266.; This operative position is shown in Fig. 17. As in the previous models described, printing is eifected at a point substantially midway between the leftward and rightward positions of toggle lever 263, when the platen 288 is impressed, against the type wheel and the projection 293 cooperates with the notch in star wheel 238 corresponding to the character selected, to index the type wheel and arrest the said type wheel momentarily to produce a clearly printed record.

With the yieldable connection of spring 294, any variation and distance between the type wheel 231 and toggle link 264 is taken up by the spring 294. For example, during the printing stroke of the toggle mechanism, the platen 288 may bear against the type wheel 231, and to prevent damage to the printing structure the toggle arrangement in straightening out may force the portion 289 upwardly against the action of spring 294 and only so much movement of platen 288 as is needed to press against type wheel 231 is imparted to portion 291.

Motor control A motor control mechanism of open line" na- 3 ture comprises a travelingcam follower arm 31 I,

Fig. 19, pivotally carried on an extension 312, Fig. 12, on armature lever 255 cooperating with the screw threaded portion 243 of collar 242 integral with power wheel 233 which rotates continuously as long as motor 231 is energized. As long as the signal receiving magnet 251 remains energized, the arm'31l will not engage with screw thread 243. In the event that magnet 251 becomes deenergized and remains so for a time greater than a predetermined time interval, say one second, the tip of the arm 311 will be moved into engagement with screw thread 243 by rotation of armature assembly 255, Fig. 12, upon release by magnet 251 and will be permitted to travel along the screw thread 243 to ultimately open a pair of contacts 313 to open the electrical circuit for the motor 231. To start the motor, upon closing the line circuit and energizing magnet 251, the armature assembly 255 will be rotated to cause the disengagement of lever 311 from the spirally conformed portion 243 of sleeve 242, whereupon a spring 314 will act to translate the arm 311 toward its normal or leftward position, as viewed in Fig. 19, to permit the contacts 313 included in the motor circuit to close to thereby start the motor. During normal telegraphic transmission operations, the extremity of arm 311 is permitted to engage its spiral cam 243 at receipt of every spacing signal impulse, but the length of the spacing periods or intervals in the code signals is insufficient to permit a prolonged engagement of arm 311 with spiral 243 to stop the motor, and each movement or oscillation of armature assembly 256 responsive to a marking signal in the line channel will cause the disengagement of the traveling screw follower tip and the return of follower arm 211 to its ineffective position by spring 314. A motor controlsystem such as here described is known as an "open line motor stop.

Third modification The embodiment of the invention disclosed in Figs. 20to 23 contemplates a printing telegraph receiver provided with a mechanical printing mechanism magnetically controlled and the substitution of cam printing for toggle printing. According to Fig. 21, a speed regulated motor 315 is mounted on a base plate 316. The armature shaft of motor 315 carries a pinion gear 315' which meshes with a drive gear 311 rotatably carried on a shaft 318 journaled in a bracket 319 mounted on a front plate 321. Gear 311 is frictionally associated with shaft 318 through the instrumentality of a friction'clutch comprising annular friction members 322 and 32-3 compressed between gear 311 and a pair of flanged collars 324 and 325. Fixed to shaft 318 are a type wheel 326, (Figs. 20, 21), a stop arm 321, Fig. 22, and a cam 328. Juxtapositioned to stop arm 321 and adapted to have a slot and locking screw adjustment therewith, is a ratchet wheel 329.

Positioned above bracket 319 is a selector magnet 331 carried upon a bracket 332 mounted on front plate 321. An armature 333 for magnet 331 is carried upon an armature lever 334 pivoted at 335, tensioned by spring 336 and adjusting screw 331 and having an arm 338 cooperating with stop arm 321. Secured to arm 338 is a spring member 339, and interposed between spring 339 and arm 338 near the lowerextremities thereof is a stud 341 carried at the upper extremity of a .catch 342 having a shouldered portion 343 which cooperates with the teeth on the ratchet wheel 329 to initiate the printing operation. A portion of the periphery of ratchet wheel 329 adjacent the stop position thereof is devoid of teeth, which space is representative of that portion of the type wheel provided with a blank space. Catch 342 is pivotally supported on a stud 344 carried by a lever 345 pivotally mounted at 346 to the front plate 321. Catch 342 is also provided with a depending arm 341 adapted to cooperate with a stud 348 carried on a pawl member 349 pivoted at 351 to a vertical lever arm 352, which in turn is pivoted at 353 to front plate 321. Lever arm 345 and pawl 349 are interconnected by a spring 354. The pawl 349 cooperates with a multi-tooth cam member 355 carried on a stud shaft 356 mounted on an adjusting plate 351 adapted to be adjustably positionable on front plate 321. Disposed above cam 355 is a printing arm 358 pivotally mounted at 359 on front plate 321. Printing arm 358 is provided with a cam follower 361 which coacts with the ratchet-like cam projections on cam 355. Printing arm 358 is also provided with laterally disposed platen 362 which is adapted to extend through front plate 321 so as to be operably disposed beneath type wheel 326. Printing arm 358 normally tends to rotate in a counterclockwise direction (as viewed in Fig. 22) due to the action of a spring 363.

Cooperating with cam 328 is the horizontal arm 364 of a bell crank assembly 365 pivotally mounted at 366 on front plate 321. The extremity of the depending arm 361 of lever 365 is connected to a spring 333 which spring imparts clockwise rotation to lever 335. Pivoted to arm 331 in proximity to its lower extremity is a latch mem" ber 338 having the end of one arm provided with a shoulder 311, the end of the other arm being secured" to a spring 312. The upper edge of member 352 is provided with stepped portions 313 and 314 to cooperate with latch arms 388 and 345 respectively.

Also pivotally carried on arm 381 of lever 385 adjacent lever 3381s a feed pawl 315 which cooperates with a tape feed ratchet 318, and an adjustable eccentric stop 311 in the manner previously described in cooperation with tape feed rollers 313 and 388 (Fig. will cause the stepping of the tape 38!.

Operation of third modification In operation the relative position of the parts shown in Fig. 22 is that assumed during the stop condition of the apparatus wherein the synchronous or regulated motor 315 is continuously running and the selector magnet 31 is energized due to the marking or stop condition of the signal line. In this position the armature lever 334 is held attracted by magnet 33l so that arm 338 is positioned to arrest the stop arm 321, thus restraining shaft 3 l8 against rotation through its frictional interconnection with gear 3. At the beginning of the start impulse the magnet 33l is deenergized and the armature lever 334 is actuated by spring 338 to effect the disengagement of arm 338 from stop arm 321. Catch 342 is also moved out of engaging relationship with ratchet wheel 329 and stop arm 321 is free to r0- tate. This rotation proceeds until the occurrence of a reversal of current in the code signal representative of the character selected, at which instant the selector magnet 33l becomes energized and arm 338 is actuated to its rightward position into position to stop the arm 321 when it shall ultimately arrive thereat. In so moving arm 338, the spring 339 causes the catch 342 to be actuated so that shoulder 343 will engage a tooth on ratchet 329. Ratchet 329 continuing to rotate will, through the engagement of shoulder 343 and said ratchet tooth, cause catch 342 to be raised until stud 344 eventually abuts stop 385 (Figs. 22 and 34). The relative positions of stop 385 and stud 344 are such that when stud 344 abuts stop 385 the rotation of the type wheel 328 will be arrested momentarily with the selected character presented opposite the platen 382, thus indexing the selected character for printing. This method of indexing is analogous to the star wheel and stabber methods hereinbefore described in connection with the other modified forms of the invention. The upwardmovement of catch 342 causes the arm 345 to be rotated in a clockwise'direction so as to disengage the extremity thereof from step 314. The extremity of arm 345 also engages the extremity of latch 389 and causes the disengagement of shoulder 3" from step 313. In response to this disengagement, arm 352 is free to be rotated by a printing spring 384, thus causing pawl 349 to be actuated in the rightward direction to rotate cam 355 a predeteremined amount equivalent to the angular movement or pitch of one tooth thereon. This movement of cam 355 effects the oscillation of printing arm 358 and brings platen 382 into engagement with type wheel 328 to effect printing. The type wheel 328, as previously mentioned, has been arrested momentarily with the selected character properly indexed, through the coaction of stud 324 and stop 33', thus preventing the printed character from becoming blurred. After the printing operation is effected, the printing arm 353 is again returned to its lower position by spring 383. As the pawl 348 is actuated rightwardly, the stud 348 thereonstrikes the depending arm 341 of catch 342 and rotates catch 342 in a counterclockwise direction to effect the disengagement of shoulder 343 from the then engaged tooth of ratchet wheel 329. It is, of course, appreciated that the sequence of events which combine to effect printing and spacing, during an actual cycle of operation, occurs very rapidly.

During the rotation of cam 328 in the cycle of operation being described, the bell crank lever 385 is rotated in a counterclockwise direction, thus carrying latch 359 toward the right to effect the reengagement of shoulder 31! and step 313. Simultaneously, the pawl 315 is actuated rightwardly (as viewed in Fig. 22) to engage the next tooth on the ratchet wheel 318. Immediately prior to the termination of cycle of rotation of cam 328, the lever arm 354 drops off the high part of cam 328, thus permitting spring 358 to rotate lever 385 sharply in a clockwise direction, effecting not only the spacing of the tape throughthe coaction of feed pawl 315 and ratchet 318, but also the return, due to the engagement of latch 31! with step 313, of member 352 to its leftward position against the action of spring 384, thus storing up energy in spring 384 pursuant to the succeeding printing operation. The structure is thus restored to the condition shown in Fig. 22.

The printing cam 355 as previously described is mounted on an adjusting plate 351. In the arrangement shown, vertical adjustment of plate 381 is effected by means of an eccentric screw 388, and the rightward and leftward adjustment of plate 351 is accomplished by means of an eccentric screw 381. It is thus seen that a universal adjustment of cam member 355 is provided.

The present invention has been disclosed in connection with certain specific embodiments thereof but it is contemplated that such embodiments are merely illustrative and that all forms coming within the scope or range of equivalency of the appended claims are intended to be covered herein.

What is claimed is:

1. In a printing telegraph receiver, a shaft, a normally energized magnet, a toggle printing means, means responsive to the deenergization of said magnet for releasing said shaft for rotation and simultaneously preparing said printing means for effective operation, and subsequently effective upon the reenergization of said magnet for toggling said printing means to effect the printing operation.

2. In a printing telegraph receiver, a single magnet responsive to monopulse isochronous code signals comprising two elements in which each element occurs but once in a signal, each element in the signal being the complement of the other element, a toggle printing means, and means responsive to the transition from one to the other of said elements to effect the operation of said toggle printing means.

3. In a printing telegraph receiver, a single magnet responsive to equal length code signals comprising two complementary elements of different nature, a toggle printing means, means eifective upon the receipt of one of said elements for preparing said means for action, and means effective uponthe transition from one to the other of said elements to consummate the action of said means.

4. In a printing telegraph receiver, a startstop shaft, a toggle printing means, a single magnet responsive to equal length code signals comprising two complementary elements of different nature, means effective upon the receipt of one of said elements for initiating the rotation of said shaft and for preparing said toggle printing means for action, and subsequently effective upon the transition from one to the other of said elements to effect initially the operation of said printing means and subsequently the arrestment of said shaft.

5. In a printing telegraph receiver, a single magnet responsive to equal length code signals, each signal comprising a first condition and a second condition of complementary periodic lengths, a toggle printing means, and means responsive to the transition from said first to said second condition to effect the operation of said printing means.

6. In a printing telegraph receiver, a startstop shaft, a toggle printing means, a single magnet responsive to equal length code signals, each signal comprising a start condition and a stop condition of complementary periodic lengths, means responsive to the start condition of a signal for initiating the rotation of said shaft and simultaneously preparing said printing means for effective operation, and further means subsequently responsive to the transition from start to stop condition to effect the toggling of said printing means to effect the printing operation.

'7. In a printing telegraph receiver, a startstop shaft, a toggle printing means, a single magnet responsive to equal length code signals, each signal comprising a start condition and a stop condition of complementary periodic lengths, means responsive to the start condition of a signal for initiating the rotation of said shaft and simultaneously preparing said printing means for effective operation, and subsequently responsive to the transition from start to stop condition to effect initially the toggling of said printing means and subsequently the arrestment of said shaft.

8. In a tape printing telegraph receiver, a single magnet responsive to equal length'code signals, each signal comprising a first condition and a second condition of complementary periodic lengths, toggle printing means, tape spacing means, and single means responsive to the transition from said first to said second condition to control simultaneously the operation of both of said means.

9. In a recorder, a single magnet responsive to equal length code signals, each signal comprising a first condition and a second condition of complementary periodic lengths, toggle printing means, indexing means for said printing means, means responsive to said first condition for preparing said toggle printing means for action, and means effective upon the transition from said first to said second condition to toggle said printing means to effect, under the control of said indexing means, the printing operation. 10. In a printing telegraph receiver, a single magnet responsive to a first signal condition and ammo" to a second signal condition, toggle printing means, a start-stop shaft, control means for said shaft, means effective in response to the first signal condition for toggling said printing means and for establishing a first predetermined condition in said control means, and means effective upon the transition from said first to said second signal condition to print and to establish a second predetermined condition in said control means. a

11. In a recording device, a single start-stop shaft carrying in fixed predetermined operative relationship to each other a type wheel and a stop arm for controlling said shaft, a toggle printingmeans, a single magnet responsive to electrical signalling conditions for controlling said printing means, and means controlled by the toggling action of said printing means for controlling said shaft.

12. In a recording device, a start-stop shaft, a toggle printing means, a single magnet responsive to electrical signalling conditions for controlling said toggle printing means, and means controlled by the toggling action of said printing means for controlling said shaft.

13. In a recording device, a start-stop shaft, a toggle printing means, a single magnet responsive to electrical signalling conditions for controlling said shaft and printing means, means controlled by the toggling action of said printing means for controlling said shaft, and means carrying said last recited means for orienting said start-stop shaft.

14. In a letter-by-letter recording device, a start-stop shaft, a toggle printing means, a single magnet having an armature responsive to electrical signalling conditions for controlling said toggle printing means, means controlled by the toggling action of said printing means for controlling said shaft, a letter spacing cam carried on said shaft, spacing mechanism operated by said spacing cam, and means for limiting the action of said spacing mechanism.

15. In a printing telegraphv receiver, a shaft,

a magnet, a toggle printing means, means controlled by said magnet for releasing said shaft for rotation and simultaneously preparing said printing means for efiective operation, and subsequently effective under control of said magnet for toggling said printing means to effect the printing operation.

16. In a recording device, a start-stop shaft, a toggle'printing means, a single magnet having an armature responsive to electrical signaling conditions for controlling said toggle printing means, means controlled by the toggling action of said armature for controlling said shaft, a spacing cam carried on said shaft, and spacing mechanism operated by said spacing cam.

17. In a recording device, a start-stopshaft, a toggle printing means, a single magnet having an armature responsive to electrical signaling conditions for controlling said toggle printing means, means controlled by the toggling action of said armature for controlling said shaft, a spacing cam carried on said shaft, spacing mechanism controlled by said cam, and means for rendering said cam effective for substantially one complete rotation of said shaft to prepare said spacing mechanism for effective action.

WALTER J. ZENNER. 

